1. Field of the Invention
The present invention relates to an apparatus and a method for protecting a motor of an inverter refrigerator, in particular to the apparatus and method for protecting the motor of the inverter refrigerator which is capable of protecting the motor of the inverter refrigerator by preventing cutting off of a power feeding on a CPU (Central Processing Unit) when an OLP (Over Load Protector) operates and interrupts the power feed.
2. Description of the Prior Art
In general, in comparison with the conventional refrigerator adopting an ON-OFF method which regularly turns on/off a compressor, an inverter refrigerator adopts a technology which can optimize cooling air discharges and electric consumption of the inverter refrigerator in accordance with circumstances by controlling optimally operating hours and operating speed of a compressor of the inverter refrigerator.
FIG. 1 is a block diagram illustrating an apparatus for protecting a motor of the inverter refrigerator according to the conventional technology. As depicted in FIG. 1, the conventional apparatus comprises an OLP ( Over Load Protector) 10 preventing damages of the motor winding by cutting off a power feeding to the motor of the compressor in accordance with a rise in temperature of the motor winding and increase of load current when the compressor does not operate well due to a certain cause or overload occurs while the compressor operates, a SMPS (Switching Mode Power Supply) 20 providing an AC power source through the OLP 10, a detector 30 detecting the present state of the refrigerator, a CPU (Central Processing Unit) 40 driven by the power of the SMPS 20, processing a detecting signal of the detector 30 and outputting a control signal for controlling operation of the refrigerator, a driving unit 50 controlling operation of the motor of the compressor by receiving a compressor control signal outputted from the CPU 40, and a display unit 60 displaying state of the refrigerator in accordance with a state control signal outputted from the CPU 40.
The operation of the conventional apparatus for protecting the motor of the inverter refrigerator will now be described.
First, when the SMPS 20 is inputted the AC power source through the OLP 10 and feeds the AC power source to the CPU 40 as an operating power, and the CPU 40 is driven by the power fed by the SMPS 20 and controls generally various parts of the refrigerator. The CPU 40 is inputted the present state of the refrigerator through the detector 30 and operates the refrigerator by controlling the driving unit 50 in accordance with the present state of the refrigerator, and informs the present state of the refrigerator to a user by controlling the display unit 60. Herein, when the overload occurs on the motor of the compressor, the temperature of the winding of the motor rises or the overload increases, the motor of the compressor is protected by cutting off the power feeding to the motor by operating of the OLP 10 connected to a power input unit of the motor.
However, in the above-described conventional apparatus for protecting the motor of the inverter refrigerator, the CPU 40 can not store hysteresis of the past driving states of the inverter refrigerator because all the power feeding to the refrigerator is cut off by operating of the OLP 10. Accordingly, the conventional apparatus can not operate properly corresponding to the present operation of the OLP of the inverter refrigerator.
It is an object of the present invention to provide an apparatus and a method for protecting a motor of an inverter refrigerator which is capable of continuing power feeding to a CPU 40 by switching a power feed line and stopping operation of the motor of a compressor when an OLP 10 drives, and operating the motor of the compressor by feeding normal power passing through the OLP 10 when the OLP 10 is in the normal state.
In order to achieve the above object, the apparatus for protecting the motor of the inverter refrigerator of the present invention comprises the OLP 10 cutting off an AC power source inputted to the motor of the compressor in overload, an OLP detector 70 detecting operation/non-operation of the OLP 10, a power select unit 80 inputted the AC power source passing through the OLP 10 and the AC power source without passing through the OLP, a CPU (Central Processing Unit) 40 outputting a power select control signal to the power select unit 80 and a driving control signal for driving the motor after being inputted a detecting signal from the OLP detector 70, a SMPS (Switching Mode Power Supply) 20 feeding a driving power to the CPU 40 after receiving the power outputted from the power select unit 80 controlled in accordance with the power select control signal outputted from the CPU 40, a driving unit 50 controlling the operation of the motor of the compressor after receiving the driving control signal outputted from the CPU 40, a detector 30 outputting a detecting signal to the CPU 40 after detecting the present state of the refrigerator, and a display unit 60 displaying the state of the refrigerator in accordance with a state control signal outputted from the CPU 40.
The method for protecting the motor of the inverter refrigerator of the present invention judges whether the OLP 10 operates by using the OLP detect unit 70, in the result of the judging step when the OLP 10 operates, the CPU 40 is fed by the AC power source without passing through the OLP 10, the CPU 40 switches the power select unit 80 from one side P2 to the other side P1 by select-controlling the power feed line, in the result of the judging step when the OLP 10 does not operate, the CPU 40 switches the power select unit 80 from the side P1 to the other side P2 by select-controlling the power feed line.